1. Field of the Invention
The present invention relates generally to folders of printing presses and more particularly to a device for folding and transporting signatures.
2. Background Information
Web printing presses print a continuous web of material, such as paper. In a folder of the printing press, the continuous web is folded by a former and cut into signatures. The signatures then may be collated in a collating device.
One way to open folded signatures to permit collation or transport is with a lap, i.e. an overlapping area on the folded signature. A device opens the signature using the lap and then trims the lap away. Trimming the lap generates significant waste and adds a step to the printing process, making the process less efficient and slower.
Another way to open folded signature is with a gripper. To open the signature, a gripping device seizes and then opens the signature. However, the gripping device can cause damage to the signature.
Thus, the need to open the signature, for example to deposit the signature on a saddle, results in significant fault generation in the bindery. The generation of significant faults requires the addition of multiple diagnostic parts to conventional saddle collation machines, which results in increased costs and reductions in reliability and productivity.
U.S. Pat. No. 3,762,697 purports to disclose a delivery apparatus for use with a folding apparatus of web-fed rotary printing machines. The paper webs are cut to copy length by cutting cylinders and then transferred to the folding blade cylinders and folded in the folding rollers. Thereafter, using the fans, the folded products are delivered to conveyor belts.
The device of the ""697 patent does not appear to provide for opening the signatures and the apparatus uses a complicated folding apparatus to fold the signatures. The fan arrangement and folding apparatus subject the device to time consuming and difficult repair and do not permit collation.
European Patent No. EP 0 479 067 B1 purports to disclose a collator for collecting and depositing signatures, apparently having a circulating first receiving device, which is constructed as an oblong conveyor with a plurality of receiving portions open towards the outside onto which the separate signatures are inserted and from which the signatures are combined to form book blocks. The book blocks are delivered to a first receiving device, which then delivers the signatures to a second receiving device, where the book blocks are removed with the aid of rear stops of adjustable height. The second receiving device then delivers the book blocks to the transport device.
With European Patent No. EP 0 479 067 B1 the signatures appear to have to enter the book blocks in the order that the signatures will be assembled, as no device is present for opening the signatures and inserting other signatures. Moreover, the device possesses a complicated arrangement of moving parts, which may make repair and servicing time consuming and expensive.
An object of the present invention is to provide for a device for eliminating or simplifying the opening or collating of a signature in a post-folding process.
The present invention provides a folder comprising:
a first cutting device to partially cut a web of material;
a former to fold the web of material, so as to form a folded web;
a stationary signature opening device located between sides of the passing folded web; and
a second cutting device located downstream from the former to sever the folded web into an at least one signature.
With the stationary opening device, e.g. a stationary sword, of the present invention, the need to open a signature with a separate device in a post-folding process is eliminated. The stationary sword can provide the opening for the signature. Thus, the present invention eliminates the need for a signature lap to open a folded signature, which results in a more economical and efficient printing process. Moreover, the present invention eliminates the need for grippers and thus, reduces damage to the signatures. The speed of the entire collation process may also be increased.
The cutting devices preferably are pairs of cutting cylinders.
Preferably, the former of the pre-fold insertion device laterally aligns the plurality of partial cuts in the web. The lateral alignment advantageously permits the second pair of cut cylinders to sever a signature from the web by cutting the web in exactly the locations that the first pair of cut cylinders did not cut.
The second pair of cut cylinders of the pre-fold insertion device may further provide a recess to allow the stationary sword to pass through. The recess provides the advantage of allowing the stationary sword to project through the second pair of cut cylinders, which allows the second pair of cut cylinders to sever the signature without contacting or damaging the stationary sword.
The stationary sword preferably increases in thickness downstream from the second pair of cut cylinders and in so doing spreads apart the edges of a signature, so as to open the signature. Advantageously, the increase in thickness allows the signature to be placed on the moving swords without the need for a gripper or other device to open the signature.
Preferably, the stationary sword has an aperture that allows a plurality of moving wedge swords to pass through the stationary sword. The aperture advantageously permits the moving wedge swords to pass through the stationary sword and in so doing pull the signatures off the stationary sword.
The present invention may further include a sword conveyor to transport a plurality of moving swords or moving wedge swords. The sword conveyor provides the advantage of allowing the signatures on the swords to proceed to additional pre-fold sword insertion devices, where the swords receive additional signatures, or continue to other steps in the collation process.
Preferably, the sword conveyor moves in a direction perpendicular to the direction of the stream of signatures.
The sword conveyor of the present invention may also move at about a 45 degree angle to the direction of the stream of signatures. Advantageously, the motion of the sword conveyor reduces the relative velocity between the signature and the sword conveyor, thus, the present invention may function at higher speeds without damaging the signature.
A collating devices with two folders according to the present invention is also provided.